Seek for a detailed description on scopes and modules

StefanKarpinski · October 17, 2018, 3:05pm

Yes, that is not assignment, it is mutation of the Dict object, which is very different:

Explicit denotation of variability and immutability

There are the following assignment-like syntaxes:

x = ... is assignment. The name x is bound to the value that the ... evaluates to. Local bindings never leak out of their scope. It doesn’t matter what x was bound to before this happens, that value is not affected in any way. No object is mutated by this and no other binding besides x is changed.

x.f = ... is equivalent to setproperty!(x, :f, ...) which, by default mutates the object x by changing its field f to the value of the expression ... . If x is visible in another scope or by another bindings, this change will be seen everywhere. No bindings are changed by this.

x[i] = ... is equivalent to setindex!(x, ..., i) which, for arrays mutates the array x by changing its i th slot to refer to the value of the expression ... . If x is visible in another scope or by another bindings, this change will be seen everywhere. No bindings are changed by this.